He is a professor at the University of Oregon, I believe. He is a member of this site, and shows up once in a blue moon. Once, he had to come in as a new user as he had lost several important email addresses. He was challenged of course, but was verified by jrap, which is all that is needed around here. So he has several active accounts, one of which is effectively dead.

If you want to contact him you can use his profile link (which in turn can be found by his occasional entry in the Feedback and Suggestions forum) and send him a direct email.